1. Field of the Invention
The presently disclosed subject matter relates to an endoscope hood, and more particularly, to an endoscope hood for fixing a probe of an optical tomographic imaging apparatus, an ultrasonic diagnostic apparatus, and the like to a region to be measured at a leading end of an insertion part of an endoscope.
2. Description of the Related Art
Up to now, diagnostic imaging has been widely carried out. In the diagnostic imaging, an insertion part of an endoscope is placed to be inserted into the body cavities of a blood vessel, a bile duct, a pancreatic duct, a stomach, an esophagus, a large intestine, and the like, and a probe placed at a leading end of the insertion part is used to perform radial scanning, whereby a tomographic image of a living body is created. As an example, in an optical coherent tomography (OCT) apparatus, an elongated optical probe with a built-in optical fiber having a leading end to which an optical lens and an optical mirror are attached is used, a signal beam is emitted in a direction substantially orthogonal to an axial direction (longitudinal direction) of the optical probe, and a return beam thereof is acquired, whereby a tomographic image of a region to be measured in the direction substantially orthogonal to the optical probe is created. Further, in the OCT apparatus, the optical mirror at the leading end of the optical fiber is rotated about the axis of the probe to perform radial scanning, whereby a tomographic image of the region to be measured in a circumferential direction of the axis of the probe is created. In addition, similarly for other measurement apparatuses such as an ultrasonic diagnostic apparatus, there has been known an apparatus in which a probe placed at a leading end of an insertion part of an endoscope is used to acquire data of a region to be measured in a direction orthogonal to an axial direction, whereby a tomographic image and the like are created. The presently disclosed subject matter is not limitatively applied to the OCT apparatus, and thus can be applied to a probe of an arbitrary apparatus. In this specification, description is given mainly of the case where the presently disclosed subject matter is applied to the optical probe for OCT.
It is desirable that the probe as described above be fixed to a region to be measured at the time of data acquisition, in order to prevent disturbance of a created image and deterioration in positional accuracy from occurring. However, in the case of observation of a living body, there are disturbances such as a body motion of the living body and hand vibrations of an operator, and hence it is difficult to fix the probe to the region to be measured in a stable state by relying only on a technique of the operator. In particular, in the case of measurement inside of the living body, body motions due to pulsation and the like cannot be stopped. Therefore, it is an important issue how to cause the probe to follow the movement of the region to be measured.
Up to now, the following methods have been generally known as the method of fixing the probe to the region to be measured. That is, Japanese Patent Application Laid-Open Nos. 2001-275942 and 2005-211433 each disclose a method in which a balloon is provided near a leading end of an insertion part of an endoscope, and the balloon is inflated so as to engage with a tube wall, to thereby fix the probe. Further, Japanese Patent Application Laid-Open Nos. 2008-054843 and 2001-275933 each disclose a method in which a hood having an opened front side is provided at a leading end of an insertion part, and is pressed against the region to be measured, to thereby fix the probe.
In addition, Japanese Patent Application Laid-Open Nos. 2004-000376 and 2003-144378 each disclose a method in which a hood provided at a leading end of an insertion part is abutted against the region to be measured, the pressure inside of the hood is reduced (air is sucked therefrom), and the hood is adsorbed onto the region to be measured, to thereby fix the probe.